An elevator car moves in an elevator hoistway in a vertical direction along a trajectory determined by the guide rails of the elevator car. In some embodiments the position of the elevator car in the elevator hoistway is measured with a magnetic switch moving along with the elevator car, which magnetic switch reacts to permanent magnets fitted into the elevator hoistway alongside the trajectory of the elevator car when the magnetic switch is situated in the immediate proximity of a permanent magnet. Permanent magnets are usually fastened by the aid of their magnetic force of attraction to a guide rail of the elevator car and a magnetic switch is disposed next to the guide rail. The permanent magnets can be disposed e.g. in such a way that they indicate the position of the elevator car in the door zone, i.e. at that point of the elevator hoistway in which passengers are able to transfer from the stopping floor into the elevator car and also to exit from the elevator car to the stopping floor. In this case the elevator car starts moving from the point of the magnet and stops at the point of the magnet in the elevator hoistway.
If a permanent magnet is located at an incorrect point of the guide rail, the elevator car will stop at the wrong point. In this case a step forms between the stopping floor and the floor of the elevator car, which step makes the transfer of passengers between the elevator car and the stopping floor awkward, causing inter alia a risk of tripping. A step also impedes e.g. the transfer of a wheelchair or castor pallet into the elevator car or out of the elevator car. For this reason an elevator fitter must adjust the position of the magnets indicating the location of the door zone by moving each magnet, e.g. from the roof of the elevator car in such a way that the step between the floor of the elevator car and the stopping floor is eliminated. This work phase lengthens the installation time of the elevator. In addition, the position of the magnets might change also during operation of the elevator, e.g. owing to vibration, air flow, et cetera, in which case a serviceman must visit the elevator to rectify the position of the magnets.